Intermolecular Interactions between Nitrosourea and Polyoxometalate compounds

AbstractHerein, the aim of this work was to investigate the intermolecular interactions between polyoxometalate (POMs) as a drug‐delivery system with nitrosourea at different sites: CH3, COOH, NH2, NO2 and OCH3 using density functional theory (DFT) at the M062X/LanL2DZ level of theory. The result showed that, the lowest bond lengths recorded for the adsorbate and the nanocage were 1.40Å, 1.64Å, 1.40Å and 1.57Å for NU/POM(CH3), NU/POM(NH2), NU/POM(NO2) and NU/POM(OCH3) respectively. The NU/POM(NO2) system had the highest adsorption energy in the three phases: −32.039, −26.95, and −29.38 kcal/mol for gas, solvent, and benzene respectively and the lowest was shown in NU/POM(OCH3) with −14.10, −10.33, −12.29 kcal/mol. The energy gap was found to be the highest in NU/POM(NO2) with 5.061eV followed by NU/POM and NU/POM(COOH) 4.020eV and 4.003eV respectively. It has been clearly shown that NU/POM(NO2) density peak in the Highest occupied molecular orbital and Lowest unoccupied molecular orbital (HOMO/LUMO) plot was above 5 and this go in line with the electronic properties possessing a stable nature. In the NBO analysis, after adsorption of the nitrosourea (NU), the NU/POM(NO2) system recorded the highest energy with 1309.42 kcal/mol and the lowest in NU/POM(OCH3) with 921.75 kcal/mol. The system with NO2 possess more stability, chemical hardness, electrophilicity index and strong interactions. It has a better surface interaction than other compounds found in Nitrosourea.